Headstock



F. S. HAAS Feb. 3, 1942.

HEADSTOCK Filed D60. 30, 1940 3 Sheets-Sheet 1 INVENTOR. fZfDfP/(l/ J". Mas

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,ilillllolllllllsf IIF I\ IL M M H Patented Feb. 3, 1942 UNITED STATES PATENT OFFICE HEADSTOCK Frederick S. Haas, Cincinnati, Ohimassignor to Cincinnati Grinders In Ohio, a corporation of Application December :0, 1940, t-ifs. 372,263 k 9 Claims.

This invention relates to machine tools and more particularly to improvements in a headstock unit therefor. it

One of the objects of this invention is to provide an improved self-contained headstock unit for machine tools.

Another object of this invention is to provide a headstock unit of the self-contained prime mover type having improved, compact mechanism for variably actuating the work driving means.

A further object of this invention is to provide an improved self-contained power driven headstock which may be selectively actuated at infinitely variable speeds as a live spindle or dead spindle headstock.

Other objects and advantages of the present invention should be readily apparent by reference to the following specification, considered in conjunction with the accompanying drawings forming a part thereof and it is to be understood that any modifications may be made in the exact structural details there shown and described, within the scope of the appended claims, without departing from or exceeding the spirit of the invention.

Figure l is a side view of the headstock unit embodying the principles of this invention.

Figure 2 is an end view of the unit shown in Figure l and as viewed from the left of that figure.

Figure 3 is a horizontal section on the line 3-4 of Figure 1.

Figure 4 is a section on the line 44 of'Flgure Figure 5 is a detail section on the line 5-5 of Figure 1.

Figure 6 is a detail section on the line 8-8 of Figure 3.

Figure "l is a detail section on the line 1-! of Figure 3.

Referring to Figure l of the drawings, the reference numeral Ill indicates the housing of the headstock unit upon the top of which is mounted a prime mover II which may preferably be an electric motor. although motors of other types may be utilized. The prime mover is attached to a slide i! by means of bolts it. As shown in Figure l, the slide I2 is provided with a dovetailed guide ll which interfits with dovetailed guide surfaces I 5 formed on the top of the housing. As shown in Figure 2, the prime mover is provided with a pulley it, which is operatively corporated, Cincinnati, hi0

i8 keyed to the end of a shaft it which isiolnfnaled in the housing Ill as shown in l 'ignre By adjusting the motor along the guideway the tension in the driving belts l'i mayt tie-adjusted. After adjustment the slide, is clamped inposltion by the hold-down bolt 2|! and the clampinz boltslis v Referring to Figure 3, the primary shaft ll drives a secondary shaft 22 through a variable speed transmission unit comprising agrst set of adjustable beveled disks 2} and 24 which are splined on the shaft l9, a second set of adjustable beveled disks 2! and 26 splined on the shaft :2, and a rigid friction ring I! which circumscribes the pairs of disks. The disk 23 is held against axial movement by the thrust bearing II while the friction cone 2 is anti-frictionally journaled by the bearing 29 in the end of an adjustable sleeve 30 The sleeve may be slidably adjusted in a bore ll formed in the wall of the housing for varying the spacing between disks 2! and II. A

The disk of the driven pair is held against axial movement by the thrust bearing 3| while the disk 2! is rotatably supported by the bearing 32 in an adjustable sleeve 83 slidably mounted in a bore II. The friction disks 24 and are simultaneously adjustable to vary the speed of the device which is accomplished by virtue of the fact that they are mounted on opposite sides of the plane of rotation of the ring 21 whereby when they are both moved toward thejleit, for instance, as viewed in Figure 3, the eil'ective driving diameter of the disks and 24 is increased while the efiective diameter of the disks 2i 26 is decreased, thus producing an increase in connected by a series of V-belts ii to a pulley 5 the rate of rotation of the shaft 22. When they are simultaneously adjusted toward the right it will be evident that a decrease in speed is efl'ected.

This adjustment iseflecte'd by the mechanism shown in Figures 4 and 5." The sleeve is provided with rack teeth 35 which areoperatively engaged by a pinion it formed integral with the shaft 31 which is journaled in the housing as shown in Figure 4. This shaft has a hand wheel 38 keyed thereto at I! and by rotating the hand wheel the sleeve 30 and cone 24 are longitudinally adjusted. The sleeve tli is operatively connected by a rod 40 to the sleeve 33. This rod carries a radial lug II which iits in a radial hole 42 in the sleeve 30, and a second radial lug 43, as shown in Figure 5. which fits in a hole 44 of the sleeve 33. Thus, the sleeves ill and 33 not only move together but in the same direction.

The hand wheel 88 has an annular surface it lusting out" is is operatively connected-to the sleeve S! by a which may he graduated to cooperate with a tired mark on a plate to to indicate the resultant speed obtained for a given position of the hand wheel. The hand wheel has a boss I! which engages a boss 48 formed on the plate 46, and the shaft TI is threaded at 49 for receiving a manually operated locking nut ill, which, when tightened, increases the friction between the faces oi. the bosses whereby the wheel is fric tionally locked in any desired position. The looking nut, 50 is provided with a knurled periphery M for facilitating rotation thereof. Thus, the variable speed unit may be adjusted to change the speed of shaft 22 and after adjustment the parts may be locked to maintain that adjustment. The shaft 22 carries another pair of beveled disks 52 and 53 which are resiliently compressed into frictional engagement with internal, beveled suriaces II and 55 respectively of a rigid friction ring 50 for driving the ring. The ring has internal annular surface 61 which trictionally e the peripheral surface it o! a rigid disk gs, g in Figure 6, for imparting rotation faceplate 6|. which is operatively conthereinb! screws ill. I beveled disk 53 is rigidly connected to the shaft 2! by a cross pin 82 and is rotatably supby. an anti-friction thrust bearing 83 in a g L the housing. The beveled disk 52 is on the shaft Hand capable of axial movement relative thereto. To this end the disk I is'i'itted in the inner race 84 of an anti-friction thrust bearing, indicated generally by the reference numeral .65, while the outer race 65 of the bearing is slidaoly mounted in a bore 81.

, nsleeve ii is threaded at 68] in the bore and terminally engages the outer race 68. An adaiso threaded in the bore and torsion spring]! having longitudinally extendin end portions 12 and II projecting into the sleeve and nut respectively.

by rotating the nut, a torsion is developed in theigspringc which in turn is transmitted to the sleeve, call-3 8 rotation thereotr in a direction to move the sleeve toward the thrust bearing and urge the disk 82 toward the disk 53. By

locking the nut against rotation with the torsion vspring under load it wlll be apparent that the :threaded connection at. 68 forms a positive abutmentjor resisting axial. retraction oi the disk 52 while the torsion in the spring is continuously aetingtoetakeup any lost. motion between the tionat engagement with the driving ring 56. The sgueeaing action of the disks 52 and 53 against the tapered sides oi the ring not only maintains tmide l ed frictional grip between the surfaces. but alsodevelops a component in a radial direction on the ring opposite to its point of contact with the disc it, therebydeveloping the desired grip between thesuriaces 51 and 68.

jlher nut III is provided with a series of radial .holes II as shown in Figure 4 for receiving a small operating lever H by. which the nut is rotated. Alter the desired torsion is obtained in the spring by clockwise rotation of the nut, the

lever is inserted in one of the radial holes wherethe cylindrical surface it of the headstock spindle TI. The spindle, in turn, is supported by antifriction bearings 18 and 19 for rotation in the housing. A work supporting center is inserted in one end of the spindle while the other end of the spindle is provided with a knurled hand wheel ill by which the spindle may be rotated independently of the face plate. Means are provided whereby the spindle may be connected to the face plate for rotation therewith whereby the headstock operates as a live center headstock, or the spindle may be locked against rotation while the face plate revolves about it. resulting in a dead center headstock. The connection is obtained by threading a circular plate 82 on the nose of the headstock at 83 and providing a notch 84 in the periphery of the plate for selective engagement by a lug 85 carried by the face plate.

This lug is integral with a radially slidable support 86 for the lug, the support being movable in a dovetailed guide 06', and a set screw 81 is threaded in the support for locking it either in a position with the lug engaging the slot. or with the lug out of engagement with the slot. A spring 88 is interposed to act on the support in a radially outward direction so that by simply loosening the locking bolt 51 disengagement will be effected between the lug 85 and the slot 84. A limiting pin ll'inay be inserted in the guideway for limiting the outward movement.

The face plate is provided with the usual driving pin 90 for engaging the work piece dog for imparting rotation thereto and it should now be evident that this rotation may be imparted regardless of whether the center is a live center or adead center.

After the headstock has been operated as a dead center headstock, the hand wheel 8| may be utilized for rotating the spindle to bring the slot N into alignment with the lug 85 for operation as a live center headstock.

In order to insure against rotation of the spindle when operating as a dead center headstock, a

stop pin M is mounted in the wall 92. This pin has a beveled end 93 for engaging a bevel-sided keyway 34 formed in the spindle ll, the bevel sides serving to takeup lost motion. A spring 95 continuously urges the pin radially inward while a cross pin 98 serves to lock the pin 9! out of engagement with the slot. By turning the pin 8l, the cross pin 98 may be aligned with notches to permit inward movement of the pin 9|.

There has thus been provided an improved self-contained headstock which is compact in construction, variable as respects speed, and which may be utilized as a live or dead spindle headstock, rendering it especially suitable for precision machine tools such as grinding machines.

What is claimed is:

1. In a headstock unit-tor grinding machines and the like, the combination of a housing having a work driving member joumaled therein, a disk operatively connected to said member, a power driven shaft lournaled in said housing, a prime mover operatively connected for driving said shaft, said shaft having a pair of oppositely beveled disks mounted thereon and operatively connected thereto, and a rigid member for transmitting motion from the shaft to the work driving member, said rigid member circumscribing all of said disks and having a pair of beveled surfaces for frictionally engaging the beveled suriaces of said pair of disks and a third surface for frictionally engaging the periphery of the disk associated with said work driving member.

2. In a headstock unit, the combination of a housing having a work driver journaled therein, a power operable shaft journaled in said housing, a pair of beveled disks mounted on said shaft, means for urging said disks toward one another, a driven disk associated with the work driver and having a cylindrical peripheral surface, a ring circumscribing all of said disks and having a pair of beveled surfaces for engaging the beveled surface of said pair of disks, and a third surface connecting said bevel surfaces and adapt ed to frictionally .ngage said cylindrical surface for the purpose of transmitting motion from said shaft to said work driver.

3. In a headstock unit for machine tools, the combination of a housing having a work driving member journaled therein, of means for effecting a non-chattering rotation of said member, comprising a prime mover mounted on the housing, a drive shaft journalcd in the housing, motion transmitting means coupling the prime mover for rotation of the shaft, an intermediate shaft journaled in the housing, a variable speed friction drive connection between said shafts, and means connecting the second shaft for rotation of the member including a pair of oppositely beveled disks mounts on the intermediate shaft, a cylindrical disk associated with the member, a rigid drive ring surrounding all of said disks and having a pair of beveled surfaces engaging the beveled surfaces of said pair of disks and a third surface for frictionally engaging the periphery of the cylindrical disk, and means for continuously urging said pair of disks toward one another to maintain a uniform friction between the surfaces of said disks and ring.

4. In a headstock unit, the combination of a housing having a work driver journaled therein, a pair of shafts journaled in said housing, a prime mover operatively connected for driving one of said shafts, an infinitely variable speed mechanism interconnecting said shafts, adjusting means for changing the speeds of said mechanism, means connecting the driven shaft to the work driver including a pair of beveled disks splined on the driven shaft, a driven disk operatively connected with the work driver and having a cylindrical peripheral surface, a ring circumscribing all of said disks and having a pair of beveled surfaces engaging the beveled surfaces of said pair of disks and a third surface interconnecting said beveled surfaces for engaging the cylindrical surface of the driven disk, and resiliently operable means for urging said pair of disks into frictional engagement with the beveled surfaces on said ring to establish a driving friction therebetween and to establish a radial component on said ring to maintain friction between the ring and the cylindrical surface of the driven disk.

5. A headstock unit for 'a machine tool comprising a housing, a work driver journaled in the housing, and means for effecting a smooth nonchattering rotation of the work driver at variable speeds including a drive shaft and a driven shaft journaled in the housing, a pair of opposed beveled driving discs carried by the drive shaft,

multiple pairs of opposed bevel driving discs carried by the driven shaft. a rigid driving ring frictionaliy connecting the drive discs of the drive shaft with one set of 'drive discs on the driven shaft for transmissionof power from the driving to driven shaft, means for positively relatively adjusting the discs of the connected pairs to vary the rate of speed transmission from the driving to driven shaft, a second rigid driving ring interconnecting the work driving member and another of the sets of opposed beveled driving discs on the driven shaft, and means for automatically urging the said latter pair of discs one toward the other to maintain proper power transmitting tension between said discs, the ring and the work driving member.

6. A headstock unit for a machine tool comprising a housing, a work driver journaled in the housing, and means for effecting a smooth nonchattering rotation of the work driver at variable speeds including a drive shaft and a driven shaft journaled in the housing, a pair of opposed beveled driving discs carried by the drive shaft, multiple pairs of opposed bevel drivingdiscs carried by the driven shaft, a rigid driving ring frictionally connecting the diive discs of the drive shaft with one set of drive discs on the driven shaft for transmission of power from the driving to driven shaft, means for positively relatively adjusting the discs of the connected pairs to vary the rate of speed transmission from the driving to driven shaft, a second rigid driving ring interconnecting the work driving member and another of the sets of opposed beveled driving discs on the driven shaft, means for automatically urging the said latter pair of discs one toward the other to maintain proper power transmitting tension between said discs, the ring and the work driving member, the work driving member having a driving disc peripherally formed for internal engagement with the circumscribing driving ring and said driving ring having an inner face formed for cooperation with the disc and adjacent beveled faces for cooperation with the beveled discs on the driven shaft.

7. A headstock unit for a machine tool comprising a housing, a work driver journaied in the housing, and means for effecting a. smooth nonchattering rotation of the work driver at variable speeds including a drive shaft and a driven shaft journaled, in the housing, a pair of opposed beveled driving discs carried by the drive shaft, multiple pairs of opposed bevel driving discs carried by the driven shaft, a rigid driving ring frictionally connecting the drive discs of the drive shaft with one set of drive discs on the driven shaft for transmission of power from the driving to driven shaft, means for positively relatively adjusting the discs of the connected pairs to vary the rate of speed transmission from the driving to driven shaft, a second rigid driving ring interconnecting the work driving member and another of the sets of opposed beveled driving discs on the driven shaft, means for automatically urging the said latter pair of discs one toward the other to maintain proper power transmitting tension between said discs, the ring and the work driving member, the work driving member having a driving disc peripherally formed for internal engagement with the circumscribing driving ring and said driving ring having an inner face formed for cooperation with the disc and adjacent beveled faces for cooperation with the beveled discs on the driven shaft, and means for varying the urge of said ring engaging discs toward each other whereby to vary the latter Dressural engagements of the driving discs with the beveled faces of the ring and the radial pressure of the ring against the disc on the work driving member.

8. A headstock structure of the character described including a housing, a work engaging spindle journaled in the housing, a work driving member journaled on the spindle for rotation therewith and with respect thereto, said driving member including a disc having an outer cylindr cal surface, a pair of opposed bevel driving discs journaled in the housing in juxtaposition to the spindle and spaced to receive the disc therebetween, a rigid driving ring of greater width than the thickness of the disc circumscribing the disc of the work driver and 'the beveled discs, said ring having beveled faces in interfitting engagement with the opposed faces of the beveled discs and an inner annular surface conforming to and in engagement with the periphery of the disc on the work driving means, means for urging the beveled discs one toward the other frictionally to engage the opposite faces of the ring, and a driven shaft in driving engagement with the discs whereby to impart a smooth rotative movement to the work driving member by way of the rigid ring and the disc on said member.

9. A headstock structure of the character described including a housing, a work engaging spindle journaled in the housing, a work driving member journaled on the spindle for rotation therewith and with respect thereto, said driving member including a disc having an outer cylindrical surface, a pair of opposed bevel drivin discs journaled in the housing in juxtaposition to the spindle and spaced to receive the disc therebetween, a rigid driving ring of greater width than the thickness of the disc circumscribing the disc of the work driver and the beveled discs, said ring having beveled faces in interfltting engagement with the opposed faces of the beveled discs and an inner annular surface conforming to and in engagement with the periphery of the disc on the work driving means, means for urging the beveled discs one toward the other frictionally to engage the opposite faces of the ring, a driven shaft in driving engagement with the discs whereby to impart a smooth rotative movement to the work driving member by way of the rigid ring and the disc on said member. said driven shaft having a lateral extension, an additional pair of opposed beveled power transmitting discs journaled in the housing and having hub portions receiving the extension of the shaft, driving connections between said disc and the shaft, and means for transmitting variable speeds to the shaft by way of said discs for actuation of the work driving member.

FREDERICK S. HAAS. 

